ERBB2 and breast cancer: Metastases to the internal mammary nodes are difficult to detect on imaging, leading to inadequate diagnosis, and treatment.[26,27] Compared to more medial tumors, outer regions tumor showed better prognosis due to the lymphatic involvement was easily detected and complete surgical management.[28] Besides, we find laterality was not regarded as a prognostic factor on OS rates of female Her-2 positive breast cancer without metastasis.